Thousands of dead fish were found floating in a river in central China following a toxic spill, state media reported, the latest in a series of pollution scandals to hit the country's water supplies.

Official Xinhua news agency said on Wednesday (September 4) that 300 workers had dredged around 100,000 kilograms of dead fish from a 40-km (25-mile) stretch of the river.

The provincial environmental protection agency had identified the Shenzhen Stock Exchange-listed Hubei Shuanghuan Science and Technology Stock as the company responsible for Monday's (September 2) spill, with ammonia levels found to be beyond acceptable levels.

The company, a manufacturer of inorganic chemicals, apologized on Friday (September 6) and said it began a week-long production halt on Wednesday and blamed the spill on a sewage release "that exceeded standard levels".